The new mandarin tree ‘RubyGS’ resulted from an induced limb mutation of ‘Daisy’ mandarin (not patented). Irradiation of ‘Daisy’ budwood was initially carried out in 1999 at Dareton, New South Wales, Australia using 30 Gy and 40 Gy radiation. Irradiated buds were budded onto seedling rootstocks, and the resulting trees planted in the field in 2001 for observation. Among those was one tree, designated Tree 29, having a limb that produced fruits with an average of 4 seeds per fruit, fewer than were found in fruits on Tree 29 as a whole (average 19 seeds per fruit) and ‘Daisy’ (average 20 seeds per fruit). Budwood from the selected limb of Tree 29 was budded onto rootstock to produce second-generation trees, which were planted in 2003. Budwood from the second-generation trees was collected in 2006, irradiated at 50 Gy, and budded onto seedling rootstock to create two new trees. One of these trees, designated Tree 29 T2, was chosen for further evaluation, and three topworked trees were established in 2011. Later that year, seven trees were propagated from budwood taken from Tree 29 T2 and the variety was designated ‘RubyGS’. ‘RubyGS’ mandarin tree has been observed and found to retain its distinguishing characteristics through successive asexually propagated generations.
‘RubyGS’ is a new and distinct mandarin tree notable primarily for its reduced number of seeds per fruit as compared to its parent ‘Daisy’ mandarin. Fruits of ‘RubyGS’ mandarin are essentially seedless, with less than one seed per fruit on average, while fruits of ‘Daisy’ mandarin typically contain 15 to 25 seeds per fruit on average. Similar variety ‘Fremont’ (not patented) typically contains 16 to 23 seeds per fruit on average. ‘RubyGS’ has been observed to be sterile under high pollen pressure. ‘RubyGS’ is further distinguished from ‘Daisy’ by its later harvest maturity.
The attached photographs were taken in 2013 at Dareton, New South Wales, Australia. Actual colors will vary with lighting conditions; color characteristics of ‘RubyGS’ mandarin should therefore be determined with reference to the observations described herein, rather than from these illustrations alone.